1. Field of the Invention
The present invention relates to technology for non-contact communication between a device such as a printer and a cartridge containing a consumable component such as an ink.
2. Description of the Related Art
After being opened, for example, after a period of about six months, the quality of the ink in ink units (ink cartridges) for ink jet printers may deteriorate as a result of the environment in which it is used. Owing to such ink deterioration, high printing quality thus may not be achieved sometimes, and the print head of the printer may be adversely affected. An example of a way to deal with this problem is to provide the ink unit with a memory device such as an EEPROM, and to make sure that data for specifying the expiration period of the ink is stored in memory. A transmitter/receiver provided in the printer main unit can communicate with the memory through contact terminals to read the data concerning the expiration period of the ink. In addition to data related to the expiration period, data such as that relating to the amount of ink remaining in each ink unit may also be stored. The contact terminals may, however, become dirty, interfering with the transmission of data from the ink unit, and the need for precise alignment between the contact terminals on the ink unit and contact structure in the printer main unit complicates printer main unit construction.
An alternative to the contact type memory such as EEPROM is a structure in which a non-contact type of memory element is provided, and radio transmission is managed by a read/write sensor provided in the printer main unit.
However, because of the substantial distance over which radio transmission occurs, radio transmissions involving the use of non-contact type memory elements can result in the accidental reading of data in nearby memory elements different from the intended memory element, that is, signals can be mixed. In the case of color ink jet printers, for example, a plurality of different ink units for a plurality of different color inks are arranged at a short pitch from each other on a carriage (ink unit support member), and because the transmitted radio waves reach several of the ink units, there sometimes occurs erroneous communication with an adjacent ink unit instead of the intended ink unit.
Attempts have been made to pre-store ID information unique to each non-contact memory element, and to have the ID information first read by the printer main unit, so as to ensure proper communication as each element was distinguished through the use of the ID information during subsequent communication. However, since the procedure for reading the ID information includes a process for preventing mixed signals, referred to as an anti-collision process, running the ID information reading process for every communication process on each unit can result in a much longer communication process overall. This is undesirable, as it may degrade printer performance.